You Shall Not Pass

My strategy was to scout out all of the colonist areas using hellions or predators, and then park a battle cruiser with a science vessel on all of the uninfected colonies, avoiding all sorts of infantry and vehicular fighting forces. I then systematically rolled through the zerg bases with a mass grouping of battle cruisers, occasionally sending one or two extra as support for my defensive groups. I protected my base with a combination of perdition/missile turrets to cut down on population cost.